I've seen it so many times in the movies and TV: a person wakes up in this futuristic world, walks by his kitchen, and a computerized voice is telling him that someone is calling him. But instead of picking up a receiver, the call is actually a video-call, and his TV is used for the conversation. If you put 2 and 2 together, this is not really that futuristic. Having a camera attached on your TV, and a VoIP SIP or Skype connection with it, is not mad science. So why don't we already have this on our TVs?

The fact that you wouln't use it for the casual phone call does not mean you wouldn't use it for anything else.

But the vast majority of phone calls are just casual calls (not to mention the fact that the sci-fi that inspired this topic only features this technology in a casual sense)

Plus lets not forget that (and generally speaking) the technology that has prevailed in the past has been technology that's enabled a lazier or more casual approach to an existing method (texting, tweeting, facebook, etc).

So sure, this technology may succeed under exception circumstances, but topic is about normal usage by people who live normal lives.